The invention relates generally to clearance estimation techniques, and more particularly to a processing system for processing clearance signals for estimating a clearance between a stationary component and a rotary component of a rotating machine.
Various types of sensors have been used to measure the distance between two objects. In addition, such sensors have been used in various applications. For example, a turbine has a turbine blade that is disposed adjacent to a shroud. The clearance between the turbine blade and the shroud varies depending on the temperature of the turbine blade. For example, the clearance between the shroud and the turbine blade is greatest when the turbine is cold and gradually decreases as the turbine heats up. It is desirable that a gap or clearance between the turbine blade and the shroud be maintained for effective operation of the turbine. A sensor may be disposed within the turbine to measure the distance between the turbine blade and the shroud. The distance may be used to direct movement of the shroud to maintain the desired displacement between the shroud and the turbine blade.
In certain applications, a capacitance probe is employed to measure the clearance between two objects. The probe is located on one of the objects and measures a capacitance with respect to the other object for estimating the clearance between the two objects. Typically, signals from the probe are transmitted to a processing system for the estimation of clearance between the two objects. Unfortunately, such processing systems may involve long processing times for processing the signals and do not provide a real-time estimation of clearance between the objects.
Accordingly, a need exists for providing a processing system for clearance estimation that provides an accurate and real-time estimation of clearance between two objects.